1. Field of the Invention
The present invention relates to sensors and, more specifically, to optical devices for detecting chemical and biological substances.
2. Description of the Related Art
Substance analyzers are used in environmental monitoring, industrial process control, and medical, analytical, and military applications. For example, biological pathogens such as salmonella are often present in meat and poultry products. Since exposure to these pathogens is a health hazard, low concentrations, typically trace amounts, need to be detected quickly and reliably.
In an analytical laboratory, specialized techniques such as mass spectrometry, chromatography, electro-chemical analysis, immunoassays, etc., are readily available to detect various chemical and biological substances (i.e., analytes) with great sensitivity and specificity. However, the available techniques are often time-consuming, labor-intensive, and/or relatively expensive. In addition, devices implementing these techniques are not adapted for portable use, nor are they adapted for use outside the laboratory.